(3R,4S)-Methyl-3-heptanol,the trail pheromone of the ant Leptogenys diminuta

We wish to thank Prof. V. Schurig (Tübingen) for lending us the columns for preliminary studies, and Prof. K. Mori (Tokyo), N. Frighetto and R. T. S. Frighetto (Erlangen) for optically active samples of 4-methyl-3-heptanol. This work was supported by the Deutsche Forschungsgemeinschaft.     

Identification of sex pheromone components of the pea midge, Contarinia pisi (Diptera: Cecidomyiidae)

 Three components in extract of pheromone glands of female pea midges, Contarinia pisi, were found to be active on male pea midge antennae by coupled gas chromatographic-electroantennographic detection. The EAD active components were identified as 2-acetoxytridecane, (2S,11S)-diacetoxytridecane, and (2S,12S)-diacetoxytridecane. A blend of these compounds proved to be highly attractive to males in windtunnel experiments. Received: 12 November 1998 / Accepted in revised form: 26 january 1999     

Effect of alginic acid decomposing bacterium on the growth of Laminaria japonica (Phaeophyceae)

We collected the diseased blades of Larninaria japonica from Yantai Sea Farm from October to December 2002, and the alginic acid decomposing bacterium on the diseased blade was isolated and purified, and was identified as A lteromonas espejiana. This bacterium was applied as the causative pathogen to infect the blades of L. japonica under laboratory conditions. The aim of the present study was to identify the effects of the bacterium on the growth of L. japonica, and to find the possibly effective mechanism. Results showed that： （1）The blades of L.japonica exhibited symptoms of lesion,bleaching and deteriortion when infected by the bacterium. and their growth and photosynthesis were dramatically suppressed. At the same time, the reactive oxygen species （ROS） generation enhanced obviously, and the relative membrane permeability increased significantly. The contents of malonaldehyde （MDA） and free fatty acid in the microsomol membrane greatly elevated, but the phospholipid content decreased. Result suggested an obvious peroxidation and deesterrification in the blades of L. japonica when infected by the bacterium. （2） The simultaneous assay on the antioxidant enzyme activities demonstrated that superoxide dismutase （SOD） and catalase （CAT） increased greatly when infected by the bacterium, but glutathione peroxidase （Gpx） and ascorbate peroxidase （APX） did not exhibit active responses to the bacterium throughout the experiment. （3） The histomorphological observations gave a distinctive evidence of the severity of the lesions as well as the relative abundance in the bacterial population on the blades after infection. The bacterium firstly invaded into the endodermis of L. japonica and gathered around there, and then resulted in the membrane damage, cells corruption and ultimately, the death of L. japonica.     

(R,Z)-5-(−)-(oct-1-enyl)oxacyclopentan-2-one,the sex pheromone of the scarab beetleAnomala cuprea

The Science of Nature -     

2,3-Dimethyl-5-(2-methylpropyl)pyrazine, a trail pheromone component of Eutetramorium mocquerysi Emery (1899) (Hymenoptera: Formicidae)

 The ant Eutetramorium mocquerysi (Myrmicinae) is endemic to the island of Madagascar. During foraging and nest emigration the ants lay recruitment trails with secretions from the poison gland. We identified three pyrazine compounds in the poison gland secretion: 2,3-dimethyl-5-(2-methylpropyl)pyrazine 1, 2,3-dimethyl-5-(3-methylbutyl)pyrazine 3, 2,3-dimethyl-5-(2-methylbutyl)pyrazine 4. Only the first component elicited trail-following behavior in the ants. We were unable to investigate whether the other pyrazine components have a synergistic function. Received: 21 February 2000 / Accepted in revised form: 27 June 2000     

A trail pheromone component of the ant Mayriella overbecki Viehmeyer (Formicidae: Myrmicinae)

 The myrmicine ant Mayriella overbecki lays recruitment trails during foraging and nest emigrations. The trail pheromone originates from the poison gland. From ten identified components of the poison gland secretions only methyl 6-methylsalicylate 1 elicited trail following behavior. Received: 6 April 2000 / Accepted in revised form: 6 June 2000